(1) Field of the Invention
This invention relates generally to fluid current motors that convert fluid energy into mechanical energy. More specifically, this invention pertains to devices that convert fluid energy from naturally occurring winds or water currents into mechanical energy. The embodiment described and shown herein is used as a windmill. Those skilled in the art are users of fluid current motors.
(2) Description of the Related Art
Fluid energy conversion devices have been in existence for many years. Although fluid energy may be embodied within either gas or liquid, there are many more devices designed to capture fluid energy from air movement or wind. There are several inherent problems encountered in the conversion of wind energy into mechanical energy due to the nature of naturally occurring winds. The primary problem is that winds are rarely constant with respect to either velocity or direction. For that reason a conversion device can seldom be counted on for a continuous supply of energy. In many locales, wind velocity is considerably variable and devices that are not capable of operating below a certain threshold wind speed are inoperative when there are light winds. Conversely, high velocity winds may cause damage to the motor or cause it to operate at dangerous speeds.
Known patented devices intended to capture the wind's energy include:
______________________________________ 4,730,119 BISCOMB 1988 4,684,817 GOLDWATER 1987 4,678,394 WILLOUGHBY 1987 4,619,585 STORM 1986 4,545,729 STORM 1985 4,457,669 CORRY 1984 4,388,041 DORR 1983 4,303,835 BAIR 1981 4,278,894 CIMAN 1981 3,995,170 GRAYBILL 1976 1,265,137 TAYLOE 1918 928,097 BARKER 1909 535,504 MILLIKEN 1895. ______________________________________
MILLIKEN discloses a windmill that is described as a useful improvement in automatic regulators for windmills. The object of the invention is to provide a cheap and stable means of utilizing the force of the wind.
BARKER discloses a windmill that has several sails which are mechanically oriented so as to derive power from the wind on a power stroke and to be positioned parallel to the wind when opposing said wind.
TAYLOE discloses a device that derives power with paddle type structures that rotate about a horizontal axis.
CIMAN discloses a wind driven power generator that comprises a plurality of blades mounted between a pair of spoked wheels on a vertical column. The blades are oriented by a vane that detects the direction of the wind so that at least one blade on the vertical column is perpendicular to the direction of the wind and the other blade or blades are parallel to said wind direction.
BAIR discloses a wind powered generator with cyclic airfoil latching. Airfoils are latched and unlatched during different phases of a rotation so that during one phase they are latched and perpendicular to the wind thereby deriving power from said wind, while in another phase they are unlatched and swing parallel to the direction of the wind so that they cause little resistance against said wind. The latching and unlatching cycle of the airfoil is determined by the wind direction and is effected by electronic means which determine the point of latching and unlatching as a function of the wind direction.
DORR discloses a rotating sail fluid current motor. The device includes one or more flexible rectangular sails mounted on a supporting frame having sail guides and drive apparatus that effect a cyclical folding and unfolding of each sail so as to make the sail resistant to the wind's current in one phase and not resistant in another.
COREY discloses a jibe mill which incorporates sails mounted on a frame. Each sail is made of flexible material and may be rolled or reefed with a spring biased weight so as to either increase or decrease the area of each sail. In another embodiment of the COREY device, the sails are made of metal and speed control is provided by hydraulic cylinders that pivot each sail.
STORM '729 discloses a wind turbine apparatus that has a plurality of sail elements secured to a circular frame. The sails are extended and retracted with weighted cables that react to wind velocity.
STORM '585 discloses an improvement over '729 in that the sail elements include deformable outer skin portions and an interior rigid form against which the sails may press. During operation, the skin portion most directly opposing the wind is pressed against the rigid interior form and the other skin portion behind the rigid form is allowed to extend away from said form. This configuration during operation gives the sail a more winglike shape thereby changing the camber of the sail element.
WILLOUGHBY discloses a fluid current driven machine employing individually self-governing energy panels. Each of the panels is journalled to a frame on bearings so that in calm winds the panel hangs vertically and presents a planar face perpendicular to the direction of wind. As the wind speed increases and the rotation of the frame increases beyond an optimum speed the panels rotate on the bearings so that they become more horizontally oriented until their planar faces are parallel to the direction of the wind offering little resistance. Additionally, the frame rotates about a horizontal axis and the device is operated within a box about its lower portion so that the panels below the horizontal axis are blocked from said wind thereby preventing them from causing resistance to said wind.
GOLDWATER discloses a valvular sail power plant which includes radially oriented sail vanes upon which there are a plurality of panels that are journalled to each vane. During one phase of operation the individual panels are closed so that their planar faces are parallel to a long axis of the vane. In this configuration the vane provides resistance to the wind and derives power. In another phase, the individual panels are allowed to swing open so that when the vane is perpendicular to the wind direction each panel's planar face is parallel to the direction of wind thereby offering little resistance to said wind. The panels are biased with springs and cords to assist in their opening and closing during operation.
BISCOMB discloses a sail driven wind motor having one or two arms that extend radially with a conventional fore-and-aft rigged sail at the distal end of each arm. There are three different designs depending upon the sites of operation; one is for land, one is for shallow water, and the other is for deep water.
Lastly, GRAYBILL discloses a wind energy conversion device that includes upright posts mounted on a framework with sails connected at said sail's midsection to the posts. The shape of each sail is governed by cords connected between the frame and outside edges of each sail. During one phase of operation the sail opens and provides resistance to the wind thereby deriving power from said wind. In another phase the sail is allowed to fold upon itself so as to provide little resistance to the wind during said sail's return cycle into the wind on the circular framework.
A common feature of many of the above described devices is that their operation is rotational either about a vertical or horizontal axis. Because of this, it is required that the device have elements that are resistant to the wind during one phase thereby deriving power from said wind and driving the motor during a power stroke. Additionally, these same elements must return against the wind to be readied for another power stroke. When returning, the elements must offer a reduced resistance to the wind so that they do not counteract the power stroke of the opposing phase of operation.
None of the disclosed devices incorporate two wheels with one being smaller than the other and the smaller being located within the larger wheel. Nor do any of the disclosed devices show two wheels, each rotating independently of the other without mechanical restraint about parallel offset axes and with only a sail element connected directly between the wheels. Furthermore, many of the disclosed devices require sophisticated mechanical systems to control the operation of the device.